Many athletic activities require the participants to perform the same or similar activities a repeated number of times, both in practice and during competitive events. For example, golfers repeatedly swing golf clubs over the course of a round or a practice session; baseball, softball, or cricket players repeatedly swing a bat or throw a ball over the course of a game or practice; yoga enthusiasts, gymnasts, and dancers repeatedly perform similar routines; basketball players repeatedly shoot free throws and other types of shots; football players repeatedly run, throw, kick, block, rush, run, etc.; sailors, kayakers, canoers, crew team members, or other “boat” based athletes repeatedly perform rowing or other motions; runners have repeated and cyclic arm and leg motions; etc.
Correct body positioning and/or motion during various portions of athletic performances can help the athlete in a variety of ways. For example, proper body positioning and/or posture during an activity can help the athlete: apply or exert a force more efficiently and/or in a better direction with respect to another object; avoid injury due to awkward positioning or landing; prevent muscle soreness; perform a more aesthetically pleasing or sound routine; etc. Trainers and coaches spend a great deal of time helping athletes develop proper body positioning and working on their “form,” in order to enhance the athletic performance and to build a repeatable and reliable action.
Working under the watchful eye of a coach or trainer can greatly improve an athlete's form or body positioning, which can result in improved athletic performances. For most people, however, a coach or trainer is not always available, and there often is no great way for the athlete, on his or her own, to check their body positioning and form because many areas of the athlete's body are not visible to him or her during the practice or performance. Human beings cannot readily “feel” the locations of various parts of their body in normal body posture or positions and/or during typical motions (e.g., a human typically cannot “feel” the position of his or her lower back or a position of the foot arch during stances or certain motions). Therefore, an athlete can easily adopt poor posture, body positioning, and/or other form degrading habits over time in a manner that deleteriously affects his/her performance.